Unravelling Main- and Side-Chain Motions in Polymers with NMR Spectroscopy and Relaxometry: The Case of Polyvinyl Butyral.

Polyvinyl butyral (PVB) is an amorphous polymer employed in many technological applications. In order to highlight the relationships between macroscopic properties and dynamics at a microscopic level, motions of the main-chain and of the propyl side-chains were investigated between - 288 °C and + 55 °C, with indicating the glass transition temperature. To this aim, a combination of solid state Nuclear Magnetic Resonance (NMR) methods was applied to two purposely synthesized PVB isotopomers: one fully protonated and the other perdeuterated on the side-chains.

Location of the H atoms in ammonium persulphate by deuteron NMR. Verification by X-ray diffraction.

It is demonstrated that H atoms can be located by the spectroscopic method of deuteron NMR. The requirement is that the 'heavy-atom' positions are known from diffraction studies. The technique allows an accuracy of the order of 0.